Positive needle cam motion



Feb. 28, 1961 A. J. COBERT POSITIVE NEEDLE CAM MOTION 2 Sheets-Sheet 1Filed Dec. 20, 195? Feb. 28, 1961 A. J. COBERT 2,972,874

POSITIVE NEEDLE CAM MOTION Filed Dec. 20, 195-: 2 Sheets-Sheet 2PGSITIVE NEEDLE CAM MOTION Arthur J. Cohert, (Ihattanoog'a, Tenn.,assignor to Beau- I tiful Bryans, Incorporated, Chattanooga,'Tenn., acorporation of Tennessee Filed Dec. 20, 1957, Ser. No. 704,071

9 Claims. 01. 66-82) The present invention relates to animproved needlemotion for a flat full-fashioned knitting machine.

It is a principal object of the invention to provide an improvedvertical needle motion for use in such machines adapted to operate atvery high speeds, in which the upward and downward movements of theneedles are effected by means of separate up and down cam and followerconnections.

It is more specifically an object of the invention to provide a verticalneedle motion of this description which is constructed and arranged toeffect the relatively extended high speed up and down movements of theneedle bars along the length of the machine with smoothness and accuracyand with a minimum of vibration and jar to the machine.

It is a further object of the invention to provide a needle verticalmotion having separate cam and follower connections for effectingrespectively the upward and.

downward movement of the needles in which provision is made for idlecoursing of the needles in a low inoperative position.

The positive needle motion both in the downward and upward direction iseffected by operation of separate up and down needle cams and followerconnections associated therewith which include separate needle motion upand down cam levers disposed in balanced -relation at opposite sides ofthe main cam shaft. This construction has the important advantage that apositive and accurate operation of the needles is insured even at veryhigh speeds, and any tendency to vibration of the machine is at the sametime reduced to a minimum. The operation of the machine is thus madesmoother and a better fabric is produced. The illustrated constructionwhich includes devices for separately disabling and disconnecting theoperation of the needle motion up and down follower connections has theadditional advantage that it provides for an automatically controlledidle coursing of the needles which is well adapted for use in connectionwith the automatic insertion and removal of the carriers from the needlefield.

A feature of the invention consists in the provision of a device whichacts independently of the similarly contoured needle up and down cams tosupport the needle vertical motion up and down cam follower levers in apredetermined angular relationship which may be adjusted to control thepressure exerted by the follower connections against the respectiveneedle up and down cams, while at the same time the two levers are heldagainst separation by a much heavier spring pressure sufficient toprevent the cam followers from leaving their respective cams. Theconstruction has the particular advantage that the follower levers areat all times maintained in operative position with respect to their camsregardless of any irregularities or differences of contour which mayexist as between the two cams. I

The several features of the invention together with the advantages to beobtained thereby will be readily appreciated by one skilled in the artfrom the following 2,972,874 Patented .Feb. 28, 1961 description takenin connection with the drawings in which:

Fig. 1 is a somewhat fragmentary section through the base of afull-fashioned knitting machine illustrating particularly the needlevertical motion mechanism;

Fig. 2 is an exploded isometric view of substantially the parts shown inFig. 1; and

Fig. 3 is a detail perspective view of the latch member and pivotalsupport for the same normally connected betweenrthe needle'verticalmotion up and down cam levers.

The positive needle cam motion which forms the subject matter of thepresent invention is shown as embodied in a full fashioned knittingmachine of ordinary description, portions of the machine frame shownincluding a lower front rail 4, a rear rail 6 and a sinker rail 8. The

on pivot shaft 14 which is in turn carried by horizontally.

extending lever arms 16 secured to a needle vertical motion rock shaft18 which extends parallel to the cam shaft 10 along the length of themachine.

Referring specifically to Fig. 1, vertical movements are imparted to theneedle bar in an upward and downward direction respectively by means ofa needle bar down cam 20 and a needle bar up cam 22, said cams 20 and 22being rigidly secured to the main cam shaft 10. Movement in a downdirection is imparted to the needle bar from the cam 26 throughconnections which include a downwardly extending follower lever 24 withfollower roll 25 secured to a hub 26on the needle vertical motion rockshaft 18. Movements are imparted to the needle.

' bar in an up direction from the needle bar up cam 22' throughconnections which include a follower lever 28 with follower roll 29which is pivotally connected together with a short reinforcing arm 3! tothe hub 26 on the needle vertical motion rock shaft 13.

As will be evident from a consideration of the drawings the followerlever 24 with follower roll 25 engages against cam 20 at one side of thecam shaft 10, whereas follower lever 28 with follower roll 29 engagesagainst its cam 22 at the opposite side of the cam shaft 10. The twoearns 26} and 22 are contoured to maintain constant the angular relationbetween the two follower levers 24 and 28.

The two levers 2d and 28 are held positively apart in the angularrelation referred to established by the contours of the cams 2t), 22 bya spacer member 34 against the pressure of a heavy spring 36. The spacermember 34 which is in the form of a flat plate or bar having a rightangle offset at its left hand as seen in Fig. 2 to which is fitted asmall shaft extension 38 which is an ranged to pass through an apertureformed in a swivel pin 40 mounted on the-cam lever arm 28. The spacermember 34 is releasably connected to the needle bar down cam followerlever 24 by the engagement of a notch formed in the spacer member 34with a pin 41 on the follower lever 24. The spacer member 34 is biasedagainst the pin 41 by means of a tension spring 42 connected between thespacer member 34 and a pin on the follower lever 24. The shaft extension38 is threaded to receive thereon an adjustable stop washer 44 whichengages against the swivel pin 49 which thus provides a means ofadjustment of the amount of spread between the two levers 24, 28. Thecam levers 24, 28 are drawn towards one another by means of a powerfulcompression spring 36 which is coiled about the shaft'extension 38 andis seated at one end against the swivel pin ttl'and at its other endagainst lock washers 48 and 50 threaded. to the outer end of the shaftextension 38 so that the aerasvc -1 shaft extension 38 is drawn throughthe swivel pin 4% to a position determined by the engagement of the stopwasher 44 therewith. The compression spring 36 thus acts to-draw the twofollower levers 24, 2% toward one another and to hold the respectivefollower rolls 25, 29 against their cams at a pressure which isdeterminedby the adjustment of the stop washer 44.

The above described arrangement permits the follower levers 24, 23 to beheld in the spaced relation determined by the contours of the two cams2t), 22 and by the spacer member 34 under a pressure sufliciently heavyto prevent any possibility of separation under the stresses of highspeed operation, while at the same time the actual pressure with whichthe follower rollers 25, 29 are forced against the earns 21 22 is heldto a predetermined low value by the adjustment of the stop washer 4 Thecams will thus not be subjected to undue wear, while at the same time upcam lever 28 and follower 29 are held in position with relation to thedown cam lever 2dto avoid any yield in the parts during the up movementof the needle bar. The spring 36 does permit the follower levers 24- and28 to yield with relation to one another if any irregularity exists inthe contours of the cams so that the levers may spread slightly to takeup the shock of any such. irregularity or deviation in the cam contours.The resulting deformation of the heavy spring 36 in any event would beso slight so as to not cause any noticeable deformation in the needlemotion. In this connection, it will be noted that there is a mechanicaladvantage between the cam rollers and the length of movement of theindividual needles in a ratio of approximately 2 to 1.

For the performance of narrowing operations, it will be understood thateach of the earns 20, 22 above described will have mounted adjacentthereto a corresponding separate narrowing cam for eifectingrespectively the up and down movements of the needle bars for narrowing.These narrowing cams are contoured to oppose each other in the samemanner as the knitting cams 22 and to preserve unchanged the establishedangular spacing between the needle up and down cam levers 24, 28. Whenthe main cam shaft 19 is shifted longitudinally to the narrowingposition, the rollers 25, 29 will be transferred from the main cams 2d,22 to the narrowing cams in the usual manner and will similarly betransferred back to their.

knitting cams when the cam shaft id is returned to the knittingposition.

In accordance with the invention the separate up and down cam actuatedneedle vertical motion above described is particularly constructed andarranged to be shifted between active operation and an idle coursingposition in which the needles are held in a low inoperative positionsuitable for the introduction and removal of yarn carriers from theknitting zone in accordance with an automatic cycle of operation of themachine. In order to condition the separate up and down cam actuatedneedle vertical motion cam follower levers 24 and 28 above de-. scribedfor idle coursing the down motion cam follower lever 24- which ispositively connected to the needle rock shaft 18 is latched in itsextreme outward position from the cam shaft in which the needles aredown, and at the same time the needle up motion cam lever 28 is renderedinoperative to raise the needles by disengagement of the spreader member34. The up cam lever 28 continues to move idly, being held against itscam 22 by means of a light spring 54 connected between the lever arm 28and lever arm 24.

The mechanism by means of which these operations of disconnecting theneedle up motion cam lever 28 and of locking the needle down cam lever24 in the idle coursing position are performed comprises a rock shaft 53extending along the length of the machine, having at intervals thereonrearwardly extending cam levers such as that shown at 60 in Fig. 2provided with a follower roller 62 adapted for engagement with an idlecoursing cam 64. The follower roller 62 is axially shiftable on a pivotpin 66 on the follower lever 60 between cam engaging and inoperativepositions. A shifting fork 68 pivoted on the follower lever 60 isoperatively connected at one end to the follower roller 62 and isconnected by means of a Bowden wire 72 with the armature shaft of a.solenoid '74 which is arranged to be operated by connections notspecifically shown from the pattern chain of the machine. A smalltension spring 75 connected between the shifting fork 68 and a point onthe machine tends normally to maintain the follower roller 62 in itsdisengaged inoperarive position. The mechanism controlled by the camfollower 6% and rock shaft 58 comprises a plurality of rearwardlyextending lever arms 76 secured to the rock shaft 58, one such lever 76,as shown in Fig. 2, being associated with each spreader link 34 alongthe length of the machine. The lever 76 is provided with a laterallyextending pin 73 adapted for engagement beneath the forward end of thespreader link 34, so that a rocking movement of the shaft 58 produced bythe idle coursing cam .54 will have the eifect of raising the link 34about the swivel pin 4% to disengage the notch in the link with the pin41, and thus to disconnect the needle motion up cam lever 28 from itsactuating mechanism including the down cam lever 24. At the same time,and as the cam down lever 24 reaches its extreme outward position, alatch lever 3t pivoted at 82 on a bracket 8 secured to the front rail 4of the machine is rocked upwardly to engage a notch in the latch leverfit with a pin 86 on the lower end of the needle motion down cam lever24, thus locking the needles in their extreme down position. Thismovement of the latch St is effected by means of a link 88 connectedbetween the latch lever St) and the idle coursing cam lever 6i). It willbe noted that the lever fill, while in its disengaged position issupported on a stop pin 90 mounted on a fixed portion of the machine ata low level which will permit the follower roller 62 carried on the camlever 66 to be readily shifted between the cam engaging and idleposition.

The idle coursing position of the needles may be maintained for a numberof revolutions of the main cam shaft 10. During the course of each suchrevolution while the follower roller 62 is in its cam engaging posi tionthe idle coursing cam lever 60 will be moved by means of a suitablecontour of the cam 64, not specifically shown, downwardly to its rollertransfer position and then upwardly to raise the spreader arm 3 andlatch while the needles are down and before the needle motion down camfollower lever 24 would normally start to follow its cam inwardly withthe rearward movement of the needle motion cam lever 28. The idlecoursing cam 64 is preferably contoured to maintain the idle coursinglever 60, and the spreader lifting lever 76 and latch lever 80 raiseduntil the down motion cam follower lever 24 and roller 25 ride againonto the high portion of the down cam 20. To avoid possible interferenceof the part the link 38 is yieldably extensible, being made of tworelatively separable elements which are normally held together to moveas a unit by means of a spring 22.

The adjustment of the spreader bar 34 and its adjusting nut 44 is suchas to cause the two cam follower rollers 25 and 29 to be held under sometension through the spring 36. The reason for this pressure consists inthe fact that slight variations have been found to exist invariably inthe diameter of the cams. if no pressure were applied on the rollers,there would he places on the periphery of the cams Where there wouldactually be displacementbetween the rollers, so that the needle barwould not then be held and guided too Well. Any lost motion or tolerancebetween the rollers and the cams would cause the needle bar to vibrateand not to follow the path of the main cam accurately. Under thesecircumstances provision must be made to overcome this pressure before itis possible to move the spreader member 34 into and out of engagementwith the locking pin 38 as above described. To this end a cutout 97 isprovided in the needle bar up motion cam 22 which is located on thehalf-round portion of the cam and not the working half, that is, on thatportion of the cam engaged by the follower roller 29 when the needle baris moving up and down. This cutout will arrive at the roller 29 duringthe thread laying part of the coulier motion when the needles aremotionless. The cutout 97 is deep enough only to release the pressurebetween the rollers and their respective cams so that at this time itwill be possible to raise and lower the spreader member 34 withoutdifliculty and thus to engage the notch in the spreader member with themating pin 41. The inward motion of the vertical needle motion up camlever 6 the spreader member 34 and latch 80 are permitted to fall. Whenthe cam 20 comes under the roller 25, it will raise the needlemotiondown cam lever 24 just far enough to release the pressure on thelatch 80 which is then permitted to drop down releasing the pin 86. Alsothe spreader member 34 will drop under the influence of its spring 42but will not fully engage the recess of the spreader member for thereason that at this point of the knitting cycle there must be somepressure between the rollers 25 and 29. However, the needle bar 12 willrise because of the tension exerted by the spring 54 as the machinecontinues to revolve, and the slope of the 28 toward the vertical motionneedle down motion cam lever 24 permitted by the cutout 97 is limited bythe engagement of a second stop member 98 with the pivot pin for theneedle vertical motion up cam lever 28. The stop member 98 is providedwith a screw adjustable stop nut 100 screw theraded to the stop member98 which is rigidly connected with a stop member 102, on the needlevertical motion down cam lever 24. The stop member 98 with itsadjustable stop nut 100 is arranged to engage against the abutment 102at the same time that the roller 29 reaches the cutout portion 97 of theneedle up motion cam 22.

The operation of the positive up and down cam and needle motionincluding the operation during idle coursing will be briefly describedas follows:

During the normal operation of knitting or narrowing the vertical needlemotion down cam lever 24, and the needle vertical motion up cam lever 28are locked together through the spreader member 34 so that the needlebar cams 20 and 22 can impart a positive motion downwardly through camfollower lever 24 to the needles, and thereafter a substantiallypositive upward motion to cam follower lever 28 backed by the heavyspring 36.

When it is desired to resort to idle coursing, as for example, duringthe automatic insertion of the reinforcing carriers from storage totheir operating position, the machine is first slowed somewhat at leastone course prior to the course in which the idler isto be used. Then atthe correct revolution in response to a signal from the pattern machineor pattern card depending on the system of automatic control, thesolenoid 74 is energized. Roller 62 is shifted from its inoperativeposition into engagement with an idle coursing cam 64 which is timed toraise the follower lever 60 during the couliering or thread laying partof the cycle. At the same time, the roller 29 of the needle verticalmotion up cam lever 28 would have reached the cutout 97 on its cam 22 sothat the spreader member 34 at its point of contact with the pin 41 willbe freed from the pressure of spring 36, with only the force of spring42 holding the members 34 down. Then as the idle coursing cam lever 60rises spring 54 will hold the respective needle up cam lever 28 andneedle down cam lever 24 against their cams 22 and 20 taking the placeof the disconnected spring 36.

The machine continues to turn until the needle bar 12 has been loweredby the action of cam 20. As the lever 24 moves outwardly pin 86 willsnap into the latch 80 which will then hold the lever 24 stationary. Theneedle bar is now at its lowest position. As the machine continues toturn the needle bar would normally rise as the needle down cam followerlever 24 tends under the influence of spring 54 to move inwardlyfollowing the down slope of its cam 20, but is not permitted to do sobecause of the engagement of the latch 80 with the pin 86. Needle upmotion cam lever 28 however following the contour of the cam will moveto the left against the action of the spring 54.

When it is desired to return the needle bar to its working position, thesolenoid 74 is released again during the normal thread laying part ofthe revolution. This action causes the roller 62 to move out of registerwith the cam 64. Then, as the machine continues to revolve,

cam 20 becomes lower. Then on the next yarn laying stroke as the roller29 reaches the cutout 97 on the cam 22, the notch formed in the spreadermember 34 will drop into engagement with the pin 41, and the idle coursecycle is thus completed.

The invention having been described What is claimed 1. In afull-fashioned knitting machine having knitting devices and knittingneedles movable as a unit in forward and back and up and downdirections, and a cam shaft, the combination of a needle up and downmotion rock shaft, separate cams on the cam shaft contoured to producerespectively the up and down movements of the needles, a needle down camfollower lever positively connected with said rock shaft and arrangedfor engagement with its cam at one side of the cam shaft, a needle upcam follower lever supported from said rock shaft at an angle withrelation to said needle down cam follower lever for engagement with itscam at the opposite side of the cam shaft from the needle down camfollower lever, said cams being contoured to maintain constant saidangle between the needle up and down cam follower levers during rotationof the cam shaft, means connected between said needle up and down camfollower levers to maintain constant the angular relation therebetweenincluding a spacing device disposed to limit the relative approach ofsaid follower levers to a minimum angular relation, spring means actingupon said follower levers to maintain said follower levers in saidminimum angular relation, and means operable to disconnect said spacingdevice and said spring means from at least one of said follower leversand thereby to permit a free relative movement thereto, and additionalspring means continuously biasing said follower levers against theirrespective cams.

2. In a full-fashioned knitting machine having knitting devices andknitting needles movable as a unit in forward and back and up and downdirections, and a cam shaft, the combination of a needle up and downmotion rock shaft, separate cams on the cam shaft contoured to producerespectively the up and down movements of the needles, a needle down camfollower lever positively connected with said rock shaft and arrangedfor engagement with its cam at one side of the cam shaft, a-needle upcam follower lever supported from said rock shaft at an angle withrelation to said needle down cam follower lever for engagement with itscam at the opposite side of the cam shaft from the needle down camfollower lever, said cams being contoured to maintain constant saidangle between the needle up and down cam follower levers during rotationof the cam shaft, and means connected between said needle up and downcam follower levers to maintain constant the angular relationtherebetween comprising a spacer member constructed and arranged topermit a relative separating movement of said levers and having meansfor adjustment to provide a minimum angle of separation between saidlevers, and yieldable means connected between said needle up camfollower lever and spacer member to maintain said levers in said minimumangle position.

3. ma full-fashioned knitting machine having knitting devices includinga series of needles movable as a unit in forward and back and up anddown directions, and a aovasve cam shaft, the combination of a needle upand down motion rock shaft, a needle up cam and a needle down cammounted on the cam shaft for producing respectively the up and downmovements of the needles, a needle down cam follower lever positivelyconnected with said rock shaft and adapted to engage its cam at one sideof said cam shaft, a needle up cam follower lever pivotally supportedfrom said rock shaft at an angle with relation to said needle down camfollower lever for en gagement with its cam at the opposite side of saidcam shaft from the needle down cam follower lever, said cams beingcontoured to maintain constant said angle between the needle up and downcam follower levers during rotation of the cam shaft, a spacing deviceconnected between said needle up and down cam follower levers arrangedto maintain said angular spacing between said cam follower levers andincluding spring means acting between said spacing device and one ofsaid cam follower levers to bias said cam follower levers toward oneanother, and means acting when rendered operative to disconnect saidspacing device from at least one of said cam follower levers.

4. In a full-fashioned knitting machine having knitting devicesincluding a series of needles movable as a unit in forward and back andup and down directions, and a cam shaft, the combination of a needle upand down motion rock shaft, a needle up cam and a needle down cammounted on the cam shaft for producing respectively the up and downmovement of the needles, a needle down cam follower lever mounted on therock shaft and adapted to engage its cam at one side of said cam shaft,a needle up cam follower lever mounted from the rock shaft at an anglewith relation to said needle down cam follower lever for engagement withits cam at the opposite side of said cam shaft from the needle down camfollower lever, said cams being contoured to maintain constant saidangle between the needle up and down cam follower levers during rotationof the cam shaft, means securing one of said follower levers rigidly tothe rock shaft, means connected between said needle up and down camfollower levers to maintain a predetermined minimum angular relationtherebetween including a spacing device disposed between said followerlevers to limit the relative approach of said follower levers, springmeans acting upon said follower levers to effect said relative approachof said follower levers and to maintain said levers in said minimumangular position, and means acting when rendered operative to disconnectsaid spacing device from between said follower levers.

5. In a full-fashioned knitting machine having knitting devicesincluding a series of needles movable as a unit in forward and back andup an down directions, and a cam shaft, the combination of a needle upand down motion rock shaft, a needle up cam and a needle down cammounted on the cam shaft for producing respectively up and downmovements of the needles, a needle down cam follower lever positivelyconnected with said rock shaft and adapted to engage the cam at one sideof said cam shaft, a needle up cam follower lever pivotally supportedfrom the rock shaft at an angle with relation to said needle down camfollower lever for engagement with its cam at the opposite side of saidcam shaft from the needle down cam follower lever, said cams beingcontoured to maintain constant said angle between the needle up and downcam follower levers during rotation of the cam shaft, and a spacingdevice connected between said cam follower levers including a separatingmember disposed between said cam follower levers and slidably supportedon one of them, an adjustable stop member on said separating member forengagement with said lever to provide a minimum angle of separation between said levers, and a heavy spring connected between said separatingmember and lever biasing the lever against said stop.

- 6. In a full-fashioned knitting machine having knitting devices andknitting needles movable as a unit in forward and back and up and downdirections, and a cam shaft, the combination of a needle up and downmotion rock shaft, separate cams on the cam shaft contoured to producerespectively the up and down movements of the needles, a needle down camfollower lever positively connected with said rock shaft and arrangedfor engagement with its cam at one side of the cam shaft, a needle upcam follower lever supported from said rock shaft at an angle withrelation to said needle down cam follower lever for engagement with itscam at the opposite side of the cam shaft from the needle down camfollower lever, said cams being contoured to maintain constant saidangle between the up and down follower levers during rotation of the camshaft, a spacer member connected between said cam follower levers, alatch operative to lock the needle down cam follower lever in an extremeoutward needle down idle coursing position, cam actuated means actingwhen rendered operative to disconnect one of said cam follower leversfrom the spacer member, and simultaneously to actuate said latch to lockthe needle down cam follower lever in said out'ward idle coursingposition.

7. In a full-fashioned knitting machine having knitting devicesincluding a series of needles movable as a unit in forward and back andup and down directions, and a cam shaft, the combination of a needlemotion including a needle up and down motion rock shaft, a needle up camand a needle down cam mounted on the cam shaft for producingrespectively up and down movements of the needles, a down cam followerlever positively connected with said rock shaft and adapted to engagethe cam at one side of said cam shaft, an up cam follower leverpivotally supported from the rock shaft at an angle with relationto-said down cam follower for engagement with its cam at the oppositeside of the cam shaft from the down cam follower, said cams beingcontoured to maintain constant said angle between the needle up and downcam follower levers during rotation of the cam shaft, and a spacingdevice connected between said cam follower levers including a separatingmember disposed between said cam follower levers having a swivelingsliding connection with the needle up cam follower lever, a separatingstop adjustable on the separating member for engagement with said needleup cam follower lever, spring means connected between the needle up camfollower lever and the separating member to engage the needle up camfollower lever against said stop, a pin and slot locking connectionbetween the separating member and the needle down cam follower lever, alatch operative to support the needle down cam follower lever 1n anextreme outward needle down idling coursing posi tion, and means actingwhen rendered operative to disconnect the separating member from theneedle down cam follower lever and for latching said needle down camfollower lever in the outward needle down idle coursing position.

8. In a full-fashioned knitting machine having knitting devicesincluding a series of needles movable as a unit in forward and back andup and down directions, and a cam shaft, the combination of a needlemotion including a needle up and down motion rock shaft, a needle upcam, and a needle down cam mounted on the cam shaft for producingrespectively up and down movements of the needles, a needle down camfollower lever posinvely connected with said rock shaft and adapted toengage its cam at one side of said cam shaft, and a needle up camfollower lever pivotally supported from the rock shaft at an angle withrelation to said needle down cam follower lever for engagement with itscam at the opposite side of said cam shaft from the down cam follower,said cams being contoured to maintain constant said angle between the upand down needle cam follower levers during rotation of the cam shaft,and a spacing device connected between said cam follower awas'm leversincluding a separating member disposed between said cam follower levershaving a swiveling sliding connection with the needle up cam followerlever, a separating stop adjustable on the separating member forengagement with said needle up cam follower lever providing a positionof minimum separation between said cam follower levers, spring meansconnected between the needle up cam follower lever and the separatingmember to engage the needle up cam follower lever against said stop, areleasable connection between the separating member and the needledowncam follower lever and means acting when rendered operative torotate the separating member about said swiveling connection and therebyto disengage said releasable connection.

9. In a full-fashioned knitting machine having knitting devicesincluding a series of needles movable as a unit in forward and back andup and down directions, and a cam shaft, the combination of a needle upand down motion rock shaft, a needle up cam and a needle down cammounted on the cam shaft for producing respectively the up and downmovement of the needles, a needle down cam follower lever mounted on therock shaft and adapted to engage its cam at one side of said cam shaft,a needle up cam follower lever mounted from the rock shaft at an anglewith relation to said needle down cam follower lever for engagement withits cam at the opposite side of said cam shaft from the needle down camfollower lever, said cams being contoured to maintain constant saidangle between the needle up and down cam follower levers during rotationof the cam shaft, means securing one of said followers rigidly to therock shaft, and a spacing device connected between said 10 needle up anddown cam follower levers including a spacer member operatively connectedbetween said cam follower levers to maintain a minimum spacingtherebetween, a heavy spring connected between said spacer member andone of said cam follower levers acting to draw said cam follower leverstogether into said minimum spacing position, means for connecting anddisconnecting said spacer member from the other of said cam followerlevers, means to latch said needle down cam follower lever in an outwardneedle down idle coursing position, cam actuated means for disconnectingsaid spacer member and simultaneously for latching said needle down camfollower lever in said needle idle coursing position, an auxiliarytension spring connected between said cam follower levers, said needleup cam having formed therein a cutout to permit further movement of thecam follower levers toward one another during the cam actuateddisconnection of the spacer member, and an auxiliary spacing deviceinterposed between said cam follower levers to limit the furtherapproach movement of said cam follower levers.

References Cited in the file of this patent UNITED STATES PATENTS978,783 Rose Dec. 13, 1910 2,242,047 Strzalkowski May 13, 1941 2,426,036Lynam Aug. 13, 1947 FOREIGN PATENTS 512,445 Belgium July 15, 1952

